The overall project goal is to standardize the administration process and promote the appropriate use of the Addiction Severity Index (ASI) in substance use treatment and research. The ASI is the most widely used structured clinical interview protocol in the field. When used by a trained technician it has good reliability and validity, but is vulnerable to misuse by untrained personnel. Specific aims are to ensure that users are well trained and to enhance the usefulness of the ASI through (1) production and dissemination of a VCR film for use in training; (2) enhancement of the ASI Instruction Manual; (3) establishment of a process for testing and certifying ASI administrators; (4) development of a normative data base; (5) establishing ASI reliability and validity for various patient populations; (6) development of software for scoring the ASI and interpreting results; and (7) publication of a newsletter providing the user community with research findings and other information pertinent to the ASI. Achievement of these aims would provide an innovative product and service of interest to the more than 600 sites world-wide which currently use the ASI, and encourage its further dissemination.